1. Field of the Invention
The present invention relates to an analog signal generator and digital circuit driver, which drives an analog signal generator and a digital circuit housed in a same apparatus together.
2. Description of the Related Art
A digital camera in the prior art generates an image signal, which is analog signal, according to a pictured image, converts the image signal to a digital signal, and then carries out some predetermined signal processing for the image signal. The digital camera comprises an imaging device, an A/D converter, a timing generator, a frame memory, and other components in order to perform such operations. These analog circuits and digital circuits are housed in the digital camera. Accordingly, an attendant problem is that noise generated by a digital circuit is mixed in an analog signal.
For example, the method of utilizing a DRAM as a frame memory of a digital camera is already known. The DRAM, which is digital circuit, requires a refresh operation for rewriting the data. But, it is possible that noise may be generated by the refresh operations and that the noise may be mixed with the image signal.
As in the above example, it is possible that noise generated by driving a digital circuit may be mixed with an analog signal flowing on an analog circuit housed in an apparatus with the digital circuit